[phobos] auto-tester and Linux_64

[Brad Roberts]

Starting tonight, Linux_64 is running the unit tests for both dmd and phobos.
That said, it's running only the subset of the tests that currently pass.  Many
tests in each suite is disabled since they fail currently, so don't get too
excited.  Additionally, the druntime tests are fully disabled since there's no
easy way right now to run just the working subset.

The point is to help prevent, or at least detect fast, regressions.

There's a rather large pile of changes that aren't checked in to the three svn
trees yet, so the state as represented by the auto-tester isn't particularly
reproducible by anyone else yet, sorry.  After the next release goes out, I'll
submit the obviously correct pieces and work with Walter for dmd and Sean for
druntime on the remaining parts.

For those that like numbers:

  There are 176 runnable dmd tests (more in the compilable and fail_compilation
areas), 50 of which still fail.

  For phobos: 75 total tests, of which 34 fail.

Later,
Brad